Thursday, April 13, 2017

BLUE HILL METEOROLOGICAL OBSERVATORY
MILTON, MASSACHUSETTS
ELEVATION 635 FEET, 10 MILES SSW OF BOSTON, MA

DAILY DISCUSSION AND CLIMATE SUMMARY
THURSDAY, APRIL 13, 2017
ALL TIMES ARE IN EASTERN STANDARD TIME

TEMPS CONTINUE TO FALL AFTER PASSAGE OF COLD FRONT

Temperatures continued to drop today returning to a more seasonable
temperature. Normal high is 54F and the high by 1:00 PM today was 55F.
Winds shifted from the light southward wind to a bit stronger and coming
from the WNW. A distant haze was visible all day but it did not obscure
visibility, which was 80 miles at both 10:00 AM and 1:00 PM.

A period of rain moved over Great Blue Hill yesterday afternoon leaving 0.01
ins. of precipitation leaving us with +2.35 inches above normal precipitation
for the year. Humidity dropped since yesterday afternoon making the air dry
this afternoon.

Today’s Observations:

7 A.M.
Weather: Scattered altocumulus
Temperature: 57F; Dew Point: 46F; Wind: ENE at 9G15 kts
Sea-level pressure: 30.27 ins. Hg, steady then rising
Visibility: 70 miles hazy
6-hr Max temp: 47F
6-hr Min temp: 39F
24-hr precip: 0.01
24-hr snowfall: 0.0 in.
BHO SA 1155 CLR 110 SCT 70 250/57/46/2909G15/027/ FEW CI ALQDS HAZY/
8/061 53011 MANUAL 70001 ASOS 70001 10047 20039

10 A.M.
Weather: Scattered stratocumulus, broken cirrus,
Temperature: 50F; Dew Point: 34F; Wind: E at 12G20 kts,
Sea-level pressure: 30.27 ins. Hg, increasing unsteadily
Visibility: 80 miles, hazy
BHO SA 1455 39 SCT E250 BKN 80 252/50/34/2612G20/027/ LGT DSNT HZ/
8/401 53002

1 P.M.
Weather: Scattered cumulus, Few cirrostratus
Temperature: 55F; Dew Point: 29F; Wind: NE at 10G17 kts,
Sea-level pressure: 30.27 ins. Hg, decreasing, then more rapidly
Visibility: 80 miles, hazy
6-hr Max temp: 55F
6-hr Min temp: 44F
BHO SA 1755 E43 SCT 80 249/55/29/25010G17/027/ FEW CS NNE-S LGT DSNT HZ/
8/105 58003 10055 20044

SUMMARY FOR WEDNESDAY, APRIL 12, 2017

TEMPERATURE (DEGREES F)
MAX…..68   NORMAL…..54
MIN…..47   NORMAL…..36
MEAN….58   NORMAL…..45

DEPARTURE FROM 30-YEAR NORMAL……………………+13
TOTAL DEPARTURE FOR THE MONTH……………………+29 [+2.4 DEGREES/DAY]

HEATING DEGREE DAYS (SEASON JUL TO JUN)
TOTAL HEATING UNITS FOR YESTERDAY……………7   DEPARTURE………-13
TOTAL HEATING UNITS FOR THE MONTH………….213   DEPARTURE………-49
TOTAL HEATING UNITS FOR THE SEASON………..5115   DEPARTURE……..-631
TOTAL HEATING UNITS LAST SEASON TO DATE……4713   DIFFERENCE…….+402

COOLING DEGREE DAYS (SEASON JAN TO DEC)
TOTAL HEATING UNITS FOR YESTERDAY……………3   DEPARTURE……….+3
TOTAL HEATING UNITS FOR THE MONTH……………3   DEPARTURE……….+3
TOTAL HEATING UNITS FOR THE SEASON…………..3   DEPARTURE……….+3
TOTAL HEATING UNITS LAST SEASON TO DATE………0   DIFFERENCE………+3

PEAK GUST AND AVERAGE WIND SPEED (MPH)
PEAK WIND GUST FOR YESTERDAY……………….26  WNW AT 11:06 P.M.
AERO……………………28  WNW AT 11:06 P.M.
ASOS……………………28  NW  AT 11:06 P.M.
DAVIS…………………..24  NW  AT 11:06 P.M. RMY N/A
FASTEST MILE FOR YESTERDAY…………………20  WNW AT 11:06 P.M.
MAXIMUM 2-MINUTE ASOS AVERAGE………………18  WNW AT  8:17 P.M.
MAXIMUM 2-MINUTE DAVIS AVERAGE……………..18  WNW AT  8:08 P.M.
AVERAGE WIND SPEED AND DIRECTION…………..9.2  W
ASOS…………………..9.4
DAVIS………………….7.9 NNW [327 deg.]

PRECIPITATION (INCHES) THROUGH THIS MORNING (EST)
TOTAL PRECIPITATION 24 HRS ENDING 7 A.M….0.01  DEPARTURE……-0.16
ASOS…………..0.01
TOTAL PRECIPITATION FOR THE MONTH……….4.27  DEPARTURE……+2.23
ASOS…………..4.28
TOTAL PRECIPITATION FOR THE YEAR……….18.39  DEPARTURE……+2.35
ASOS……………N/A ***
*** ASOS annual total not available due to erroneous readings

SNOWFALL (INCHES) THROUGH THIS MORNING (EST)
TOTAL SNOWFALL 24 HRS ENDING 7 A.M……….0.0  DEPARTURE…….-0.1
TOTAL SNOWFALL FOR THE MONTH…………….2.7  DEPARTURE…….+0.8
TOTAL SNOWFALL FOR THE SEASON…………..66.4  DEPARTURE…….+4.8

PRELIMINARY CLIMATE SUMMARY FOR APRIL CALENDAR DAY DATA
DATE: MAX/MIN/MEAN/DEP/PRECIP/SNOW/SUN(MIN.)/SUN(%)/PEAK GUST/AERO/RMY GUST
AERO: Aerovane wind recording system gust
RMY:  R.M. Young wind gust recording system
TSTM: Thunderstorm day (thunder heard some time during day)
….: Data not yet available, records not finalized
M:    Missing data

4/1  35/31/33/-8/2.21/2.7/000/00           40 ENE AERO 41 ENE RMY 41
4/2  53/30/42/+1/0.00/0.0/…/..           32 NW  AERO 33 NW  RMY 34
4/3  60/35/48/+6/0.00/0.0/…/..           21 W   AERO 20 NW  RMY N/A
4/4  42/35/39/-3/0.78/0.0/…/..           41 ESE AERO 43 ESE RMY 42
4/5  41/35/38/-5/0.00/0.0/000/00           21 NNW AERO 20 NNW RMY N/A
4/6  55/35/45/+2/1.27/0.0/000/00           35 SSE AERO 37 S   RMY 37  TSTM
4/7  53/38/46/+3/0.00/0.0/…/..           43 SSW AERO 47 SSW RMY 48
4/8  50/34/42/-2/0.00/0.0/…/..           37 WNW AERO 40 WNW RMY 39
4/9  65/34/50/+6/0.00/0.0/…/..           23 W   AERO 23 W   RMY N/A
4/10 77/45/61/+16/0.00/0.0/…/..          37 S   AERO 37 S   RMY 39
4/11 85/50/68/+23/0.00/0.0/…/..          28 S   AERO 28 S   RMY 30
4/12 68/47/58/+13/0.01/0.0/…/..          26 WNW AERO 28 WNW RMY N/A

4/13 Low temp since midnight is 40F; normal low is now 37F

DAILY RECORDS FOR APRIL 2017

4/11/17: DAILY RECORD MAXIMUM TEMPERATURE OF 85F,
BREAKS PREVIOUS RECORD OF 78F SET IN 1945

4/11/17: DAILY RECORD HIGH MINIMUM TEMPERATURE OF 50F,
TIES WITH PREVIOUS RECORD SET IN 1955

DAILY EXTREMES
Temperature and precipitation records back to 1885, and
wind records back to 1940 (e = estimated):

RECORDS FOR APRIL 13
HIGH 85 IN 1945
LOW 22 IN 1939
PRECIP 2.51 IN. IN 2004
SNOWFALL 6.8 IN. IN 1933
PEAK GUST 59 MPH SSW IN 1995

RECORDS FOR APRIL 14
HIGH 80 IN 1945
LOW 21 IN 1923
PRECIP 2.22 IN. IN 1895
SNOWFALL 8.4 IN. IN 1953
PEAK GUST 71e MPH W IN 1943

TODAY’S REPORT PREPARED BY: Kaitlin Ann Geagan